Numerical Simulation of Inverse Diffusion Combustion and Flow Characteristics in a Trapped Vortex Combustor

In this work, the cold and combustion flow characteristics of a trapped vortex combustor with inverse diffusion combustion method have been studied numerically, and the effects of four jet arrangement schemes on the vortex structure, temperature distribution, turbulence kinetic energy, OH mass fraction and combustion efficiency were compared. The results indicate that the vortex structures in cold state are basically the same with a double vortex structure for all the jet schemes. However, when the jet holes are arranged on the after-body wall, the vortex changes from a double vortex structure in cold state to a single vortex structure in combustion state, the combustion effect is not too large when the jet holes are arranged on the fore-body wall. The high-temperature distribution in cavity is mainly concentrated in the upper part, but when the jet holes are arranged on the after-body wall, the OH mass fraction distribution is higher than that when the jet holes are arranged on the fore-body wall. In addition, when the jet holes are arranged on the fore-body wall, complete combustion can be accelerated. In general, when the jet holes are arranged in the same position, the multi-jet scheme is more conducive to flame stability in cavity and the improvement of combustion and mixing performance than the coaxial jet.

Automated summary

The study on a trapped vortex combustor with inverse diffusion combustion method reveals significant impacts of jet hole arrangement on vortex structure, temperature distribution, turbulence kinetic energy, OH mass fraction, and combustion efficiency. Changing the jet holes from fore-body wall to after-body wall can alter the vortex structure and increase OH mass fraction, enhancing combustion efficiency. Multi-jet schemes are more beneficial to flame stability and combustion performance improvement than coaxial jet when holes are arranged in the same position.